I have had RL140's running on a 5500 system for over 20 years.  I am now having more and more problems with different components of the 5500 and have decided I need to replace the system.  The RL140's sound fantastic so I want to keep them and buy a 3rd party receiver/amp and CD player.

The system is in a large room about 5m x 20m with timber floors and a lot of glass.

Considering buying Yamaha but I am becoming very confused with what power the amp should have.  Had originally thought of Yamaha's RX797 which is rated at 100W but a salesman has told me that since it is rated at 100W RMS it is probably too powerful for the speakers and they will blow.  He recommends the lower spec RX497B of 75W RMS. 

Which would be better?  Another complication is that the stereo system is at a holiday house which is also used by other people (as well as my kids) so I have no control over the volume setting.

And to connect up, is it any more difficult than just running the cable from speaker to amp?

Thanks,
David